Field of the Invention
The invention relates to an air pressure cylinder, and in particular to a multi-stage air pressure cylinder.
The cylinder according to the invention is particularly characterized by an assembly of separate components which are superposed substantially in the form of layers. According to the invention, supplemental stages can be added by the introduction of additional intermediate layers i.e. the introduction of some of the components.
The new cylinder is also characterized by its restricted builkiness which is needed in the robotic field.
The compact shape of the new cylinder facilitates its cleaning operation. It also allows an electroless nickel phosphorous coating on all the piston surfaces, including all the cavities and hard anodize on the surfaces requiring lubrification.
Multipiston pressure cylinders are usually assembled inside a common sleeve of a predetermined length and such a sleeve accepts a predetermined number of pistons. The number of pistons cannot be multiplied. The limitation of such multipiston pressure cylinder is examplied in U.S. Pat. Nos 3,485,141, 3,554,088 and 3,752,040.
In the patent to Ott et al No. 3,485,141, the numbers of piston is limited by the length of the outer sleeve and the inner piston pilot tube. The same applies to the hollow cylindrical body in the patent to Bruyn No 3,554,088 and to the tubular housing in Pat. No. 3,752,040.